The root cause is from the recent wacom firmware update logic patch which is in the critical path of the boot up time - https://chromium-review.googlesource.com/c/chromiumos/platform/touch_updater/+/753268


2018-02-03T05:56:12.284241+00:00 WARNING kernel: [    8.297856] ---[ end trace 6912d3f09cd65d6d ]---
2018-02-03T05:56:13.294519+00:00 INFO chapsd[1764]: Finished importing 0 pending objects.
2018-02-03T05:56:13.299587+00:00 INFO chapsd[1764]: Master key is ready for token at /var/lib/chaps
2018-02-03T05:56:13.480438+00:00 INFO cryptohomed[1794]: TPM error 0x2020 (Key not found in persistent storage): LoadKeyByUuid: failed LoadKeyByUUID
2018-02-03T05:56:13.480493+00:00 WARNING cryptohomed[1794]: Canceled creating cryptohome key - TPM is not ready.
2018-02-03T05:56:13.480535+00:00 WARNING cryptohomed[1794]: Could not load the device policy file.
2018-02-03T05:56:13.480717+00:00 ERR cryptohomed[1794]: Creating new salt at /home/.shadow/salt (0, 0)
2018-02-03T05:56:13.639073+00:00 WARNING cryptohomed[1794]: Init() failed to read attributes file.
2018-02-03T05:56:13.973999+00:00 INFO minijail0[1522]: libminijail[1522]: child process 1527 exited with status 255
2018-02-03T05:56:13.980989+00:00 NOTICE chromeos-wacom-touch-firmware-update[1805]: Wacom device hardware ID dectected as: 0000_0000
2018-02-03T05:56:13.986219+00:00 NOTICE chromeos-wacom-touch-firmware-update[1807]: Wacom device Product ID (derived from hardware ID): 0000
2018-02-03T05:56:13.996057+00:00 NOTICE chromeos-wacom-touch-firmware-update[1811]: Attempting to find FW_V2: /lib/firmware/wacom2_firmware.hex
2018-02-03T05:56:14.001258+00:00 NOTICE chromeos-wacom-touch-firmware-update[1813]: Wacom fw v2 not found. Will use v1.
2018-02-03T05:56:14.009710+00:00 NOTICE chromeos-wacom-touch-firmware-update[1817]: Attempting to Load FW: '/lib/firmware/wacom_firmware.hex'
2018-02-03T05:56:14.028920+00:00 NOTICE chromeos-wacom-touch-firmware-update[1825]: Active firmware version: 0
2018-02-03T05:56:14.033362+00:00 NOTICE chromeos-wacom-touch-firmware-update[1827]: New firmware version: 1539
2018-02-03T05:56:14.041674+00:00 NOTICE chromeos-wacom-touch-firmware-update[1831]: Update needed, firmware out of date.
2018-02-03T05:56:14.046979+00:00 NOTICE chromeos-wacom-touch-firmware-update[1834]: Update FW to 1539
2018-02-03T05:56:14.239418+00:00 INFO cryptohomed[1794]: Attestation: Valid attestation data exists.
2018-02-03T05:56:14.324251+00:00 INFO cryptohomed[1794]: Cannot read boot lockbox files.
2018-02-03T05:56:28.716959+00:00 NOTICE chromeos-wacom-touch-firmware-update[1846]: Update FW succeded. Current Firmware: 1539
2018-02-03T05:56:28.722443+00:00 NOTICE chromeos-wacom-touch-firmware-update[1850]: Attempting to re-bind 'i2c-ACPI0C50:00' to driver '/sys/bus/i2c/drivers/i2c_hid'
2018-02-03T05:56:28.763091+00:00 ERR kernel: [   24.776396] i2c_hid i2c-ACPI0C50:00: error in i2c_hid_init_report size:76 / ret_size:0
2018-02-03T05:56:28.764041+00:00 INFO kernel: [   24.777147] input: ACPI0C50:00 2D1F:0163 as /devices/pci0000:00/0000:00:15.2/i2c_designware.2/i2c-8/i2c-ACPI0C50:00/0018:2D1F:0163.0002/input/input9
2018-02-03T05:56:28.764059+00:00 INFO kernel: [   24.777567] hid-generic 0018:2D1F:0163.0002: input,hidraw0: <UNKNOWN> HID v1.00 Device [ACPI0C50:00 2D1F:0163] on 
2018-02-03T05:56:28.769559+00:00 NOTICE chromeos-wacom-touch-firmware-update[1860]: Success.
2018-02-03T05:56:28.845029+00:00 ERR kernel: [   24.857625] i2c_hid i2c-ACPI0C50:00: i2c_hid_get_input: incomplete report (13/512)
2018-02-03T05:56:28.863525+00:00 WARNING session_manager[1884]: [WARNING:libpolicy.cc(35)] Could not load the device policy file.
2018-02-03T05:56:28.863863+00:00 INFO session_manager[1884]: [INFO:session_manager_main.cc(212)] Will wait 3s for graceful browser exit.
2018-02-03T05:56:28.896492+00:00 INFO session_manager[1884]: [INFO:session_manager_service.cc(157)] SessionManagerService starting

Issue 809353 has been merged into this issue.

Potential duplicate: https://partnerissuetracker.corp.google.com/issues/73572072

Issue 820135 has been merged into this issue.

The issue should be fixed now (in R66 and R67). R65 merge was rejected.